Chap. XVI] DUCTLESS GLANDS 317 



Little is known of the function of this gland, but the results of 

 various experiments justify the belief that the secretion of both 

 the anterior and posterior lobes has an important influence upon 

 metabolism. The secretion of the anterior lobe is connected with 

 growth, particularly of the skeleton. The secretion of the pos- 

 terior lobe has a specific effect upon the organs of circulation, in- 

 creases the secretion of urine and milk, and is connected in some 

 way with the metabolism of carbohydrates. There seems to be 

 an inter-relation between the hypophysis, and the pancreas, adre- 

 nals, and thyroid. 



Gigantism, or excessive growth, and dwarfism, or underdevelop- 

 ment, are thought to be due to abnormal conditions of this gland 

 in early life. In later life abnormal conditions are attended with 

 enlargement of the bones of the extremities and the features of 

 the face, a condition known as acromegaly. 



(6) The epiphysis. — The epiphysis or pineal body is a small 

 reddish gray body located in the third ventricle of the brain. 

 In early life it is glandular and attains its maximum growth about 

 the seventh year. After this period, and particularly after puberty, 

 it decreases in size, and the glandular tissue is replaced by fibrous 

 tissue. It is thought that in early life the gland furnishes a se- 

 cretion that inhibits growth, and restrains the development of the 

 reproductive glands. 



(7) The carotid glands. — They are so named because each is 

 situated in the bifurcation of a common carotid artery. They 

 are composed of nodules, each of which is a mass of epithelial 

 cells, among which are large capillaries. They are covered by a 

 fibrous capsule. 



(S) Coccygeal gland. — The coccygeal gland is situated in front 

 of the tip of the coccyx. It is co^•e^ed by fibrous tissue and com- 

 posed of epithelial cells. 



SPLEEN 



Some authorities class the spleen with the ductless glands ; 

 other authorities question this, as it has not been possible to de- 

 monstrate that it furnishes an internal secretion. It is directly 

 beneath the diaphragm, l)ehind and to the left of the stomach. 

 It is covered by a portion of the peritoneum, the serous membrane 

 covering the viscera of the abdomen. It is bean-shaped, convex on 

 the outer surface, concave on the inner, and weighs usually from 



